The standard of review is a legal principle that dictates the level of deference a reviewing court gives to the decisions made by a lower court or administrative agency. It establishes the framework within which an appellate court evaluates the legal and factual determinations of the lower tribunal, impacting whether the decision will be upheld or overturned. Different standards, such as 'de novo,' 'abuse of discretion,' or 'clear error,' are applied based on the type of issue being reviewed.